Hydrophobic coating including DLC on substrate

ABSTRACT

A substrate is coated with a hydrophobic coating that includes highly tetrahedral amorphous carbon that is a form of diamond-like carbon (DLC). In certain embodiments, the coating is deposited on the substrate in a manner to increase its hydrophobicity (e.g. so that the coating has an initial contact angle θ of at least about 100 degrees; and/or a surface energy of no more than about 20.2 mN/m). In certain embodiments, the coating is deposited in a manner such that it has an average hardness of at least about 10 GPa, more preferably from about 20-80 GPa.

[0001] This is a continuation-in-part (CIP) of U.S. patent applicationSer. No. 09/303,548, filed May 3, 1999, the disclosure of which ishereby incorporated herein by reference.

[0002] This invention relates to a hydrophobic coating includingdiamond-like carbon (DLC) provided on (directly or indirectly) asubstrate of glass, plastic, or the like, and a method of making thesame. The coating may be deposited on the substrate utilizing plasma ionbeam deposition in certain embodiments.

BACKGROUND OF THE INVENTION

[0003] Conventional soda inclusive glasses are susceptible toenvironmental corrosion which occurs when sodium (Na) diffuses from orleaves the glass interior, as well as to retaining water on theirsurfaces in many different environments, including when used asautomotive windows (e.g. backlites, side windows, and/or windshields).When water is retained or collects on automotive windows, the water mayfreeze (i.e. forming ice) in certain environments. Additionally, themore water retained on a windshield, the higher power wiper motor(s)and/or wiper blade(s) required.

[0004] In view of the above, it is apparent that there exists a need inthe art for (i) a coated article (e.g. coated glass or plasticsubstrate) that can repel water and/or dirt, and a method of making thesame, (ii) a coated soda inclusive glass where the coating(s) reducesthe likelihood of visible stains/corrosion forming; and/or (iii) aprotective hydrophobic coating for window, glass, or plastic substratesthat is somewhat resistant to scratching, damage, or the like.

[0005] It is known to provide diamond like carbon (DLC) coatings onglass. U.S. Pat. No. 5,637,353, for example, states that DLC may beapplied on glass. Unfortunately, the DLC of the '353 patent would notbe-an efficient hydrophobic coating and/or would not be an efficientcorrosion minimizer on glass in many instances.

[0006] U.S. Pat. No. 5,900,342 to Visser et al. discloses a fluorinatedDLC layer on an electrophotographic element. From about 25-65% fluorinecontent by atomic percentage is provided at an outermost surface, toprovide for low surface energy in an attempt to make removal ofxerographic toner easier. Unfortunately, this DLC inclusive layer of the'342 patent would be too soft for use on a glass substrate in automotiveapplications and the like. Its apparent lack of SP C—C bonds and/or lackof Si—O bonds contribute to its softness. It is also believed thatcontinuous exposure to sun, rain, humidity, dust, windshield wipers,and/or the environment in general would cause the '342 DLC layer tobreak down or degrade rather quickly over time.

[0007] Thus, there also exists a need in the art for a DLC inclusivelayer that has sufficient hardness and durability to withstand theenvironment while still exhibiting satisfactory hydrophobic qualities.

[0008] It is a purpose of different embodiments of this invention tofulfill any or all of the above described needs in the art, and/or otherneeds which will become apparent to the skilled artisan once given thefollowing disclosure.

SUMMARY OF THE INVENTION

[0009] An object of this invention is to provide a durable coatedarticle that can shed or repel water (e.g. automotive windshield,automotive backlite, automotive side window, architectural window,etc.).

[0010] Another object of this invention is to provide a coatedsubstrate, wherein a coating includes sp³ carbon-carbon bonds and has awettability W with regard to water of less than or equal to about 23mN/m, more preferably less than or equal to about 21 mN/m, and mostpreferably less than or equal to about 20 mN/m, and in most preferredembodiments less than or equal to about 19 mN/meter. This can also beexplained or measured in Joules per unit area (mJ/m²)

[0011] Another object of this invention is to provide a coatedsubstrate, wherein a coating includes sp³ carbon-carbon bonds and has asurface energy Y_(C) of less than or equal to about 20.2 mN/m, morepreferably less than or equal to about 19.5 mN/m, and most preferablyless than or equal to about 18 mN/m.

[0012] Another object of this invention is to provide a coatedsubstrate, wherein a DLC inclusive coating has an initial (i.e. prior tobeing exposed to environmental tests, rubbing tests, acid tests, UVtests, or the like) water contact angle θ of at least about 100 degrees,more preferably of at least about 110 degrees, even more preferably ofat least about 115 degrees, and most preferably of at least about 125degrees.

[0013] Another object of this invention is to provide a coating for asubstrate, wherein at least about 15% (more preferably at least about25%, and most preferably at least about 30%) of the bonds in the coatingare sp³ carbon-carbon (C—C) bonds; and wherein the coating includes byatomic percentage at least about 5% silicon (Si) atoms (more preferablyat least about 15%, and most preferably at least about 20% Si), at leastabout 5% oxygen (O) atoms (more preferably at least about 15% and mostpreferably at least about 20%), at least about 5% hydrogen (H) atoms(more preferably at least about 10% and most preferably at least about15%) taking into consideration either the coating's entire thickness oronly a thin layer portion thereof. In certain embodiments, an increasedpercentage of H atoms may be provided near the coating's outermostsurface. In certain embodiments, the coating has approximately the sameamount of C and Si atoms.

[0014] Another object of this invention is to provide a coating for aglass substrate, wherein the coating includes a greater number of Sp³carbon-carbon (C—C) bonds than sp² carbon-carbon (C—C) bonds. In certainof these embodiments, the coating need not include any sp² carbon-carbon(C—C) bonds.

[0015] Another object of this invention is to provide a coated glassarticle wherein a DLC coating-protects the glass from acids such as HF,nitric, and sodium hydroxide (the coating may be substantiallychemically inert).

[0016] Another object of this invention is to provide a coated glassarticle that is abrasion resistant.

[0017] Another object of this invention is to provide a DLC coating on asubstrate, wherein the coating includes different portions or layerswith different densities and different sp³ carbon-carbon bondpercentages. The ratio of sp³ to sp² carbon-carbon bonds may bedifferent in different layers or portions of the coating. Such a coatingwith varying compositions therein may be continuously formed by varyingthe ion energy used in the deposition process so that stresses in thecoating are reduced in the interfacial portion/layer of the DLC coatingimmediately adjacent the underlying substrate. Thus, a DLC coating mayhave therein an interfacial layer with a given density and Sp³carbon-carbon bond percentage, and another layer portion proximate amid-section of the coating having a higher density of Sp³ carbon-carbon(C—C) bonds. The outermost layer portion at the surface of the coatingmay be doped (e.g. addition of Si, O and/or F) so that this surfaceportion of the coating is less dense which increases contact angle anddecreases the dispersive component of surface energy so as to improvehydrophobic characteristics of the coating.

[0018] Another object of this invention is to manufacture a coatinghaving hydrophobic qualities wherein the temperature of an underlyingglass substrate may be less than about 200° C., preferably less thanabout 150° C., most preferably less than about 80° C., during thedeposition of a DLC inclusive coating. This reduces graphitizationduring the deposition process, as well as reduces detempering and/ordamage to low-E coatings already on the substrate in certainembodiments.

[0019] Generally speaking, this invention fulfills any or all of theabove described needs or objects by providing a coated articlecomprising:

[0020] a substrate (e.g. glass or plastic);

[0021] a coating including diamond-like carbon (DLC) provided on saidsubstrate, said coating including sp³ carbon-carbon bonds; and

[0022] wherein said coating has an initial contact angle θ with a dropof water of at least about 100 degrees, and an average hardness of atleast about 10 GPa.

[0023] This invention further fulfills any or all of the above describedneeds and/or objects by providing a coated glass article comprising:

[0024] a glass substrate; and

[0025] a coating including diamond-like carbon (DLC) provided on saidglass substrate, wherein the outermost 5Å of said coating includes inatomic percentage at least about 50% H.

[0026] This invention further fulfills any or all of the above describedneeds and/or objects by providing a coated glass article comprising:

[0027] a glass substrate comprising, on a weight basis:

[0028] SiO₂ from about 60-80%,

[0029] Na₂O from about 10-20%,

[0030] CaO from about 0-16%,

[0031] K₂O from about 0-10%,

[0032] Mgo from about 0-10%,

[0033] Al₂O₃ from about 0-5%;

[0034] a hydrophobic coating including diamond-like carbon (DLC) and sp³carbon-carbon bonds provided on said glass substrate; and

[0035] wherein said hydrophobic coating has an initial contact angle θwith a sessile drop of water of at least about 100 degrees, and anaverage hardness of at least about 10 GPa.

[0036] This invention further fulfills any or all of the above describedneeds and/or objects by providing a method of making a coated article,the method comprising the steps of:

[0037] providing a substrate; and

[0038] depositing a highly tetrahedral amorphous carbon (ta—C) inclusivecoating having more sp³ carbon-carbon bonds than sp2 carbon-carbon bondson the substrate in a manner such that the ta—C inclusive coating has aninitial contact angle θ of at least about 100 degrees.

[0039] In certain embodiments, the method includes plasma treating anoutmost surface of the coating in order to provide at least H atoms inthe coating proximate the outermost surface thereof so as to reducesurface energy of the coating.

[0040] This invention will now be described with respect to certainembodiments thereof, along with reference to the accompanyingillustrations.

IN THE DRAWINGS

[0041]FIG. 1 is a side cross sectional view of a coated articleaccording to an embodiment of this invention, wherein a glass or plasticsubstrate is provided with a DLC inclusive coating thereon havinghydrophobic qualities.

[0042]FIG. 2 is a side cross sectional view of a coated articleaccording to another embodiment of this invention, wherein first andsecond DLC inclusive coatings are provided on a substrate of glass orplastic.

[0043]FIG. 3 is a side cross sectional view of a coated articleaccording to yet another embodiment of this invention wherein a low-E orother coating is provided on a substrate, with the hydrophobic DLCinclusive coating(s) of either of the FIG. 1 or FIG. 2 embodiments alsoon the substrate but over top of the intermediate low-E or othercoating.

[0044]FIG. 4 illustrates exemplar sp³ orbitals of carbon in atetrahedral state.

[0045]FIG. 5 illustrates exemplar orbitals of carbon in a sp² state(i.e. graphitic).

[0046]FIG. 6 illustrates exemplar sp hybridizations of a carbon atom.

[0047]FIG. 7 is a side cross sectional view of carbon ions penetratingthe substrate or growing DLC coating surface so as to strongly bond aDLC layer to an underlying DLC layer or other substrate according to anyembodiment herein.

[0048]FIG. 8 is a side cross sectional view of a coated glass substrateaccording to an embodiment of this invention, illustrating at least DLCbonds of the coating penetrating cracks in the surface of a glasssubstrate.

[0049]FIG. 9 is a perspective view of a linear ion beam source which maybe used in any embodiment of this invention for depositing a DLCinclusive coating.

[0050]FIG. 10 is a cross sectional view of the linear ion beam source ofFIG. 9.

[0051]FIG. 11 is a side cross sectional partially schematic viewillustrating a low contact angle θ of a drop on a glass substrate.

[0052]FIG. 12 is a side cross sectional partially schematic viewillustrating-the coated article of the FIG. 1 embodiment and the contactangle θ of a water drop thereon.

[0053]FIG. 13 is a schematic diagram of an assembly for manufacturing acoated article according to an embodiment of this invention.

[0054]FIG. 14 is a binding energy (eV) versus counts graph of a coatedarticle according to an embodiment of this invention, taken by x-rayphoto electron spectroscopy (XPS).

[0055]FIG. 15 is a binding energy (eV) versus counts graph of the coatedarticle of FIG. 14 in another eV region, taken by XPS.

[0056]FIG. 16 is a wavelength (nm) versus index of refraction (n) andextinction coefficient (k) according to an embodiment of this invention.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS OF THIS INVENTION

[0057] Referring now more particularly to the accompanying drawings inwhich like reference numerals indicate like elements throughout theaccompanying views.

[0058]FIG. 1 is a side cross sectional view of a coated articleaccording to an embodiment of this invention, wherein at least onediamond-like carbon (DLC) inclusive protective coating(s) 3 is provideddirectly on substrate 1. Substrate 1 may be of glass, plastic, or thelike. DLC inclusive coating 3 in the FIG. 1 embodiment includes at leastone layer including highly tetrahedral amorphous carbon (ta—C). Coating3 functions in a hydrophobic manner (i.e. it is characterized by highwater contact angles θ and/or low surface energies as described below).In certain embodiments, coating 3 may be from about 50-1,000Å thick,more preferably from about 100-500Å thick, and most preferably fromabout 150-200Å thick.

[0059] In certain embodiments, hydrophobic coating 3 may have anapproximately uniform distribution of sp³ carbon-carbon bonds throughouta large portion of its thickness, so that much of the coating hasapproximately the same density. In other more preferred embodiments,hydrophobic coating 3 may include a lesser percentage of sp³carbon-carbon bonds near the interface with substrate 1, with thepercentage or ratio of sp³ carbon-carbon bonds increasing throughout thethickness of the coating toward the outermost surface. Thus, coating 3may include at least one interfacing layer directly adjacent substrate1, this interfacing layer having a lesser density and a lesserpercentage of sp³ carbon-carbon bonds than the middle portion of DLCinclusive coating 3. In general, the network of sp³ carbon-carbon bondsfunctions to hold the other atoms (e.g. Si, O, F, and/or H atoms) aroundit in the coating. In certain embodiments, it is desired to keep numberof sp² carbon-carbon bonds throughout the entire thickness of thecoating to no greater than about 25%, more preferably no greater thanabout 10%, and most preferably from about 0-5%, as these type bonds arehydrophillic in nature and attract water and the like. Thus, inpreferred embodiments, at least about 50% (more preferably at leastabout 75%, and most preferably at least about 90%) or the carbon-carbonbonds in coating 3 are of the sp³ carbon-carbon type.

[0060] The presence of sp³ carbon-carbon bonds in coating 3 increasesthe density and hardness of the coating, thereby enabling it tosatisfactorily function in automotive environments. In certainembodiments, taking only a thin layer portion of, or alternatively theentire thickness of, coating 3 into consideration, at least about 15%(more preferably at least about 25%, and most preferably at least about30%) of the bonds in the coating or coating layer portion are sp³carbon-carbon (C—C) bonds (as opposed to sp² carbon-carbon bonds).Coating may or may not include sp² carbon-carbon bonds in differentembodiments (if so, most sp² carbon-carbon bonds may be provided at theportion of the coating interfacing with the underlying substrate).

[0061] In order to improve the hydrophobic nature of coating 3, atomsother than carbon (C) are provided in the coating in different amountsin different embodiments. For example, in certain embodiments of thisinvention coating 3 (taking the entire coating thickness, or only a thin10Å thick layer portion thereof into consideration) may include inaddition to the carbon atoms of the sp³ carbon-carbon bonds, by atomicpercentage, at least about 5% silicon (Si) atoms (more preferably atleast about 15%, and most preferably at least about 20% Si), at leastabout 5% oxygen (O) atoms (more preferably at least about 15% and mostpreferably at least about 20% O), at least about 5% hydrogen (H) atoms(more preferably at least about 10% and most preferably at least about15% H). In certain preferred embodiments, the atomic percentage of C andSi atoms in coating 3 are approximately equal. Optionally, coating 3 mayinclude and from about 0-10% (atomic percentage) fluorine (F) (morepreferably from about 0-5% F) in order to further enhance hydrophobiccharacteristics of the coating.

[0062] In certain embodiments, the outermost thin layer portion ofhydrophobic coating 3 may also include a larger percentage of H atomsdeposited via plasma ion beam treatment relative to the rest of thecoating in order to reduce the number of polar bonds at the coating'ssurface, thereby improving the coating's hydrophobic properties byreducing the polar component of the surface energy. For example, incertain embodiments the outermost 5Å layer portion of coating 3 mayinclude at least about 10% H atoms, more preferably at least about 25% Hatoms, and most preferably at least about 50% H atoms. This higherconcentration or percentage of H atoms near the surface of coating 3 isillustrated in FIGS. 1-3 by the dots which become more concentrated nearthe coating's surface. The deposition of these H atoms near thecoating's surface results in a more passive or non-polar coatingsurface. It is noted that deposition of the H atoms near the coating'ssurface may tend to etch away any sp² or graphite C—C bonds in thatarea. This increase in H near the coating's surface also decreases thecoating's density at this outermost 5Å layer portion.

[0063] Accordingly, in certain preferred embodiments of this invention,coating 3 as a whole or any 10Å thick layer portion thereof (e.g. a 10Åthick portion near the middle of the coating) may include in atomicpercentage: from about 15-80% carbon (C) (mostly via sp³ bonds), fromabout 5-45% oxygen (O), from about 5-45% silicon (Si), from about 0-30%hydrogen (H), and from about 0-10% fluorine (F). The outermost 5Å layerportion of coating 3 may include in atomic percentage: from about 5-60%carbon (C) (mostly via sp³ bonds), from about 0-40% oxygen (O), fromabout 0-40% silicon (Si), from about 10-60% hydrogen (H), and from about0-10% fluorine (F). As discussed above, additional H may be provided atthe outermost portion of layer 3, largely at the expense of C, in orderto reduce surface energy. An example of a 10Å thick layer portion nearthe middle of coating 3 is as follows, by atomic percentage: 35% C, 30%Si, 15% H, and 20% O. An example of the outermost 5Å thick layer portionof coating 3 is as follows, by atomic percentage: 20% C, 15% Si, 50% H,and 15% O. Optionally, in certain preferred embodiments, from about 0-5%F may also be provided in this outermost 5Å thick layer portion. It isnoted that many of the Si, H, O, and F atoms in the coating areconnected to many carbon atoms via sp³ bonds. A substantial number ofSi-O, C—C Si-C sp³, and C-H sp³ bonds are thus present. In certainembodiments, the Si-O bonds tend to cancel out some of the charge due tothe carbon thereby reducing surface energy. The presence of the O alsoreduces density and permits the dispersive component of surface energyto be reduced. These examples are for purposes of example only, and arenot intended to be limiting in any way.

[0064] In certain preferred embodiments, coating 3 has an averagehardness of at least about 10 GPa, more preferably at least about 20GPa, and most preferably from about 20-50 GPa. Such hardness renderscoating 3 resistant to scratching, solvents, and the like. It is notedthat the hardness and density of coating 3 and/or layer 5 may beadjusted by varying the ion energy of the depositing apparatus orprocess described below.

[0065]FIG. 2 is a side cross sectional view of a coated articleaccording to another embodiment of this invention, including substrate 1(e.g. glass), hydrophobic DLC inclusive coating 3 as described abovewith regard to the FIG. 1 embodiment, and intermediate DLC inclusivelayer 5 sandwiched therebetween. In certain embodiments, at least about35% of the bonds in layer 5 may be of the sp³ C—C type, more preferablyat least about 70%, and most preferably at least about 80%. Any of theDLC inclusive layers described in Ser. No. 09/303,548 (incorporatedherein by reference) may be used as layer 5. In effect, layer 5 mayfunction in certain embodiments to reduce corrosion of the coatedarticle (e.g. when the substrate includes Na, or is soda-lime-silicaglass), while overlying coating 3 provides a hydrophobic function.

[0066] In the FIG. 3 embodiment, a low-E or other coating 7 is providedbetween substrate 1 and hydrophobic DLC inclusive coating 3. However,coating 3 is still on substrate 1 in the FIG. 3 embodiment. The term“on” herein means that substrate 1 supports DLC coating 3 or any layerportion thereof, regardless of whether or not other layer(s) (e.g. 5, 7)are provided therebetween. Thus, protective coating 3 may be provideddirectly on substrate 1 as shown in FIG. 1, or may be provided onsubstrate 1 with a low-E or other coating(s) 5 therebetween as shown inFIGS. 2-3. In still other embodiments, a low-E coating(s) 7 may beprovided between hydrophobic coating 3 and DLC layer 5 of the FIG. 2embodiment).

[0067] Exemplar coatings (in full or any portion of these coatings) thatmay be used as low-E or other coating(s) 7 are shown and/or described inany of U.S. Pat. Nos. 5,837,108, 5,800,933, 5,770,321, 5,557,462,5,514,476, 5,425,861, 5,344,718, 5,376,455, 5,298,048, 5,242,560,5,229,194, 5,188,887 and 4,960,645,which are all hereby incorporatedherein by reference. Silicon oxide and/or silicon nitride coating(s) mayalso be used as coating(s) 7.

[0068] As will be discussed in more detail below, highly tetrahedralamorphous carbon (ta—C) forms sp³ carbon-carbon bonds, and is a specialform of diamond-like carbon (DLC). The amounts of sp³ bonds may bemeasured using Raman finger-printing and/or electron energy lossspectroscopy. A high amount of sp³ bonds increases the density of alayer, thereby making it stronger and allowing it to reduce sodadiffusion to the surface of the coated article. However, in certainembodiments, there is a lesser percentage of such bonds at the outmostlayer portion of coating 3 than at middle areas of the coating, so thatH atoms may be provided in order to improve the coating's hydrophobiccharacteristics.

[0069] For purposes of simplicity, FIG. 4 illustrates orbitals of a Catom in a tetrahedral or sp³ state (i.e. capable of forming carbon tocarbon sp³ diamond like bonds) in coating 3 or layer 5. FIG. 5 is anexample of Sp² C orbitals, and FIG. 6 an example of sp hybridization ofa carbon atom. It would be recognized by those of skill in the art thatthe angles shown in FIGS. 4-5 are for purposes of example only, are notlimiting, and may be changed in different embodiments of this invention.Thus, regarding FIG. 4 for example, in certain embodiments of thisinvention orbitals in C—C sp³ bonds may be from about 100-120 degreesapart. The angles of FIG. 5 may vary in a similar manner.

[0070] In certain embodiments, coating 3 is at least about 75%transparent to or transmissive of visible light rays, preferably atleast about 85%, and most preferably at least about 95%.

[0071] When substrate 1 is of glass, it may be from about 1.5 to 5.0 mmthick, preferably from about 2.3 to 4.8 mm thick, and most preferablyfrom about 3.7 to 4.8 mm thick. Thus, ta—C inclusive coating 3 and/orlayer 5 reduce the amount of soda that can reach the surface of thecoated article and cause stains/corrosion. In certain embodiments,substrate 1 includes, on a weight basis, from about 60-80% SiO₂, fromabout 10-20% Na₂O, from about 0-16% CaO, from about 0-10% K₂O, fromabout 0-10% MgO, and from about 0-5% Al₂O₃. In certain otherembodiments, substrate 1 may be soda lime silica glass including, on aweight basis, from about 66-75% SiO₂, from about 10-20% Na₂O, from about5-15% CaO, from about 0-5% MgO, from about 0-5% Al₂O₃, and from about0-5% K₂O. Most preferably, substrate 1 is soda lime silica glassincluding, by weight, from about 70-74% SiO₂, from about 12-16% Na₂O,from about 7-12% CaO, from about 3.5 to 4.5% MgO, from about 0 to 2.0%Al₂O₃, from about 0-5% K₂O, and from about 0.08 to 0.15% iron oxide.Soda lime silica glass according to any of the above embodiments mayhave a density of from about 150 to 160 pounds percubic foot (preferablyabout 156), an average short term bending strength of from about 6,500to 7,500 psi (preferably about 7,000 psi), a specific heat (0-100degrees C.) of about 0.20 Btu/lbF, a softening point of from about 1330to 1345 degrees F., a thermal conductivity of from about 0.52 to 0.57Btu/hrftF, and a coefficient of linear expansion (room temperature to350 degrees C.) of from about 4.7 to 5.0×10⁻⁶ degrees F. In certainembodiments, any glass disclosed in U.S. Pat. No. 5,214,008 or Pat. No.5,877,103, each incorporated herein by reference, may be used assubstrate 1. Also, soda lime silica float glass available from GuardianIndustries Corp., Auburn Hills, Mich., may be used as substrate 1.

[0072] Any such aforesaid glass substrate 1 may be, for example, green,blue or grey in color when appropriate colorant(s) are provided in theglass in certain embodiments.

[0073] In certain other embodiments of this invention, substrate 1 maybe of borosilicate glass, or of substantially transparent plastic. Incertain borosilicate embodiments, the substrate 1 may include from about75-85% SiO₂, from about 0-5% Na₂O, from about 0 to 4% Al₂O₃, from about0-5% K₂O, from about 8-15% B₂O₃, and from about 0-5% Li₂O.

[0074] In still further embodiments, an automotive window (e.g.windshield or side window) including any of the above glass substrateslaminated to a plastic substrate may combine to make up substrate 1,with the coating 3 of any of the FIGS. 1-3 embodiments provided on theoutside surface of such a window. In other embodiments, substrate 1 mayinclude first and second glass sheets of any of the above mentionedglass materials laminated to one another, for use in window (e.g.automotive windshield, residential window, commercial architecturalwindow, automotive side window, vacuum IG window, automotive backlightor back window, etc.) and other similar environments.

[0075] When substrate 1 of any of the aforesaid materials is coated withat least DLC coating 3 according to any of the FIGS. 1-3 embodiments,the resulting coated article has the following characteristics incertain embodiments: visible transmittance (Ill. A) greater than about60% (preferably greater than about 70%, and most preferably greater thanabout 80%), UV (ultraviolet) transmittance less than about 38%, totalsolar transmittance less than about 45%, and IR (infrared) transmittanceless than about 35% (preferably less than about 25%, and most preferablyless than about 21%). Visible, “total solar”, UV, and IR transmittancemeasuring techniques are set forth in Pat. No. 5,800,933, as well as the'008 patent, incorporated herein by reference.

[0076] Hydrophobic performance of coating 3 in any of the aboveembodiments is a function of contact angle θ, surface energy y, andwettability or adhesion energy W. The surface energy y of coating 3 maybe calculated by measuring its contact angle θ (contact angle θ isillustrated in FIGS. 11-12). A sessile drop 31 of a liquid such as wateris placed on the coating as shown in FIG. 12. A contact angle θ betweenthe drop 31 and underlying coating 31 appears, defining an angledepending upon the interface tension between the three phases in thepoint of contact. Generally, the surface energy Y_(C) of coating 3 canbe determined by the addition of a polar and a dispersive component, asfollows: Y_(C)=Y_(CP)+Y_(CD), where Y_(CP) is the coating's polarcomponent and Y_(CD) the coating's dispersive component. The polarcomponent of the surface energy represents the interactions of thesurface which is mainly based on dipoles, while the dispersive componentrepresents, for example, van der Waals forces, based upon electronicinteractions. Generally speaking, the lower the surface energy Y_(C) ofcoating 3, the more hydrophobic the coating and the higher the contactangle θ.

[0077] Adhesion energy (or wettability) W can be understood as aninteraction between polar with polar, and dispersive with dispersiveforces, between coating 3 and a liquid thereon such as water. Y^(P) isthe product of the polar aspects of liquid tension and coating/substratetension; while Y^(P) is the product of the dispersive forces of liquidtension and coating/substrate tension. In other words,y^(P)=Y_(LP)*Y_(CP); and Y^(D)=Y_(LD)*Y_(CD); where Y_(LP) is the polaraspect of the liquid (e.g. water), Y_(CP) is the polar aspect of coating3; Y_(LD) is the dispersive aspect of liquid (e.g. water), and Y_(CD) isthe dispersive aspect of coating 3. It is noted that adhesion energy (oreffective interactive energy) W, using the extended Fowkes equation, maybe determined by:

[0078] W=[Y_(LP)*Y_(CP)]^(½)+[Y_(LD)*Y_(CD)]^(½)=Y₁ (1+cosθ), where Y₁is liquid tension and θ is the contact angle. W of two materials (e.g.coating 3 and water thereon) is a measure of wettability indicative ofhow hydrophobic the coating is.

[0079] When analyzing the degree of hydrophobicity of coating 3 withregard to water, it is noted that for water Y_(LP) is 51 mN/m and Y_(LD)is 22 mN/m. In certain embodiments of this invention, the polar aspectY_(CP) of surface energy of coating 3 is from about 0 to 0.2 (morepreferably variable or tunable between 0 and 0.1) and the dispersiveaspect Y_(CD) of the surface energy of coating 3 is from about 16-22mN/m (more preferably from about 16-20 mN/m).

[0080] Using the above-listed numbers, according to certain embodimentsof this invention, the surface energy Y_(C) of coating 3 is less than orequal to about 20.2 mN/m, more preferably less than or equal to about19.5 mN/m, and most preferably less than or equal to about 18.0 mN/m;and the adhesion energy W between water and coating 3 is less than about25 mN/m, more preferably less than about 23 mN/m, even more preferablyless than about 20 mN/m, and most preferably less than about 19 mN/m.These low values of adhesion energy W and coating 3 surface energyY_(C), and the high initial contact angles θ achievable, illustrate theimproved hydrophobic nature of coatings 3 according to differentembodiments of this invention.

[0081] The initial contact angle θ of a conventional glass substrate 1with sessile water drop 31 thereon is typically from about 22-24degrees, as illustrated in FIG. 11. Thus, conventional glass substratesare not particularly hydrophobic in nature. The provision of coating(s)3 on substrate 1 causes the contact angle θ to increase to the anglesdiscussed above, as shown in FIG. 12 for example, thereby improving thehydrophobic nature of the article. As discussed in Table 1 of09/303,548, the contact angle θ of a ta—C DLC layer is typically fromabout 5 to 50 degrees. However, the makeup of DLC-inclusive coating 3described herein enables the initial contact angle θ between coating 3and a water drop (i.e. sessile drop 31 of water) to be increased incertain embodiments to at least about 100 degrees, more preferably atleast about 110 degrees, even more preferably at least about 115degrees, and most preferably at least about 125 degrees, therebyimproving the hydrophobic characteristics of the DLC-inclusive material.An “initial” contact angle θ means prior to exposure to environmentalconditions such as sun, rain, humidity, etc.

[0082] Referring to FIG. 8, it is noted that the surface of a glasssubstrate 1 often has tiny cracks or microcracks defined therein. Thesecracks may weaken glass by orders of magnitude, especially when waterseeps therein and ruptures further bonds. Another advantage of certainembodiments of this invention is that amorphous carbon atoms and/ornetworks of DLC inclusive coating 3 (or DLC inclusive layer 5) fill inor collect in these small cracks because of the small size of carbonatoms (e.g. less than about 100 pm radius atomic, most preferably lessthan about 80 pm, and most preferably about 76.7 pm) and because of theion energy of 200 to 1,000 eV, preferably about 400-500 eV, andmomentum. This increases the mechanical strength of the glass 1. Thenanocracks in the glass surface shown in FIG. 8 may sometimes be fromabout 0.4 nm to 1 nm in width. The inert nature and size of the carbonatoms in these nonocracks will prevent water from attacking bonds at thecrack tip 14 and weakening the glass. The carbon atoms make their way topositions adjacent the tips 14 of these cracks, due to their size andenergy. Tips 14 of these cracks are, typically, from about 0.5 to 50 nmbelow the glass substrate surface.

[0083] FIGS. 9-10 illustrate an exemplary linear or direct ion beamsource 25 which may be used to deposit coating 3, layer 5, clean asubstrate, or surface plasma treat a DLC inclusive coating according todifferent embodiments of this invention. Ion beam source 25 includesgas/power inlet 26, anode 27, grounded cathode magnet portion 28, magnetpoles 29, and insulators 30. A 3kV DC power supply may be used forsource 25 in some embodiments. Linear source ion deposition allows forsubstantially uniform deposition of coating 3 as to thickness andstoichiometry.

[0084] Ion beam source 25 is based upon a known gridless ion sourcedesign. The linear source is composed of a linear shell (which is thecathode and grounded) inside of which lies a concentric anode (which isat a positive potential). This geometry of cathode-anode and magneticfield 33 gives rise to a close drift condition. The magnetic fieldconfiguration further gives rise to an anode layer that allows thelinear ion beam source to work absent any electron emitter. The anodelayer ion source can also work in a reactive mode (e.g. with oxygen andnitrogen). The source includes a metal housing with a slit in a shape ofa race track as shown in FIGS. 9-10. The hollow housing is at groundpotential. The anode electrode is situated within the cathode body(though electrically insulated) and is positioned just below the slit.The anode can be connected to a positive potential as high was 3,000volts. Both electrodes may be water cooled in certain embodiments.Feedstock gases are fed through the cavity between the anode andcathode. The linear ion source also contains a labyrinth system thatdistributes the precursor gas (e.g. gaseous mixture of TMS (i.e.(CH₃)₄Si or tetramethyl silane) and O₂; or mixture of 3MS (i.e.(CH₃)₃Si—H) and O₂) evenly along its length and which allows it tosupersonically expand between the anode-cathode space internally. TMSand 3MS are commercial available from Dow Chemical. The electricalenergy then cracks the gas to produce a plasma within the source. Theions are expelled out at energies in the order of eVc-a/2 when thevoltage is Vc-a. The ion beam emanating from the slit is approximatelyuniform in the longitudinal direction and has a gaussian profile in thetransverse direction. Exemplary ions 34 are shown in FIG. 10. A sourceas long as one meter may be made, although sources of different lengthsare anticipated in different embodiments of this invention. Finally,electron layer 35 is shown in FIG. 10 completes the circuit therebyenabling the ion beam source to function properly.

[0085]FIG. 13 illustrates an assembly for manufacturing a coated articleaccording to any of the FIG. 1-2 embodiments of this invention; theassembly including first, second, and third linear ion beam sources 61,62 and 63, respectively. These three ion beam sources may be of the typeshown in FIGS. 9-10, or alternatively may be other types of ion beamsources (e.g. filtered arc type on beam sources). Conveyor 64 functionsto move substrates through the assembly, from one source to the next.

[0086] Referring to FIGS. 1, 9, 10; 12 and 13, an exemplary method ofdepositing a coating 3 on substrate 1 will now be described. This methodis for purposes of example only.

[0087] Prior to coating 3 being formed on glass substrate 1, the topsurface of substrate 1 is preferably cleaned by way of first linear ordirect ion beam source 61. For example, a glow discharge in argon (Ar)gas or mixtures of Ar/O₂ (alternatively CF₄ plasma) may be used toremove any impurities on the substrate surface, by source 61. Suchinteractions are physio-chemical in nature. This cleaning creates freeradicals on the substrate surface that subsequently can be reacted withother monomers yielding substrate surfaces with specialized properties.The power used may be from about 100-300 Watts. Substrate 1 may also becleaned by, for example, sputter cleaning the substrate prior to actualdeposition of coating 3; using oxygen and/or carbon atoms at an ionenergy of from about 800 to 1200 eV, most preferably about 1,000 eV.

[0088] After cleaning, the deposition process begins using a linear ionbeam deposition technique via second ion beam source 62; with conveyor64 having moved the cleaned substrate 1 from first source 61 to aposition under second source 62 as shown in FIG. 13. Ion beam source 62functions to deposit a ta—C/SiO (or ta—C/SiO:F in alternativeembodiments) coating 3 onto substrate 1, as follows. In preferredembodiments; the ratio of C to Si in coating 3 is approximately 1:1(i.e. 1:1 plus/minus about 20%). However, in other preferred embodiments(e.g. see XPS analyzed Sample Nos. 1-3 below), the ratio of C to Si incoating 3 may be from about 1:1 to 4:1. The dopant gas may be producedby bubbling a carrier gas (e.g. C₂H₂) through the precursor monomer(e.g. TMS or 3MS) held at about 70 degrees C (well below the flashingpoint). Acetylene feedstock gas (C₂H₂) is used in certain embodiments toprevent or minimize/reduce polymerization and to obtain an appropriateenergy to allow the ions to penetrate the substrate 1 or other surfaceand subimplant therein, thereby causing coating 3 atoms to intermix withthe surface of substrate 1 (or the surface of the growing coating) a fewatom layers thereinto. In alternative embodiments, the dopant gas may beproduced by heating or warming the monomer (e.g. to about 25-30 degreesC.) so that vapor therefrom proceeds through a mass flow controller tothe ion beam source; so that C₂H₂ is not needed. The actual gas flow maybe controlled by a mass flow controller (MFC) which may be heated toabout 70 degrees C. Oxygen (O₂) gas is independently flowed through anMFC. In certain embodiments, a target consisting essentially ofapproximately equal molar percentages of C and Si may be isostaticallycompressed at about 20 MPa. The temperature of substrate 1 may be roomtemperature; an arc power of about 1000 W may be used; precursor gasflow may be about 25 sccm; the base pressure may be about 10⁻⁶ Torr, anda Hoescht type carbon electrode may be used. Coating 3 is preferablyfree of pinholes to achieve satisfactory water repulsion and/orsuppression of soda diffusion.

[0089] The C—C sp³ bonding in coating 3 is preferably formed by having apredetermined range of ion energy prior to reaching substrate 1, orprior to reaching a coating or layer growing on the substrate. Theoptimal ion energy window for the majority of coating 3 is from about100-200 eV (preferably from about 100-150 eV) per carbon ion. At theseenergies, the carbon in coating 3 (and layer 5) emulates diamond, andsp³ C—C bonds form in coating 3. However, compressive stresses candevelop in ta-C when being deposited at 100-150 eV. Such stress canreach as high as 10 GPa and can potentially cause delamination from manysubstrates. It has been found that these stresses can be controlled anddecreased by increasing the ion energy during the deposition process toa range of from about 200-1,000 eV. The plasma ion beam source enablesion energy to be controlled within different ranges in an industrialprocess for large area deposition utilized herein. The compressivestress in amorphous carbon is thus decreased significantly at thishigher ion energy range of 200-1,000 eV.

[0090] High stress is undesirable in the thin interfacing portion ofcoating 3 that directly contacts the surface of a glass substrate 1 inthe FIG. 1 embodiment (and the thin interfacing layer portion of layer 5in the FIG. 2 embodiment). Thus, for example, the first 1-40% thickness(preferably the first 1-20% and most preferably the first 5-10%thickness) of coating 3 (or layer 5) is deposited on substrate 1 usinghigh anti-stress energy levels of from about 200-1,000 eV, preferablyfrom about 400-500 eV. Then, after this initial interfacing layerportion of coating 3 has been grown, the ion energy in the iondeposition process is decreased (either quickly or gradually whiledeposition continues) to about 100-200 eV, preferably from about 100-150eV, to grow the remainder of coating 3 (or layer 5). Thus, in certainembodiments, because of the adjustment in ion energy during thedeposition process, DLC inclusive coating 3 in FIGS. 1-3 has differentdensities and different percentages of sp³ C—C bonds at different layerportions thereof (the lower the ion energy, the more sp³ C—C bonds andthe higher the density).

[0091] While direct ion beam deposition techniques are preferred incertain embodiments, other methods of deposition may also be used indifferent embodiments. For example, filtered cathodic vacuum arc ionbeam techniques may be used to deposit coating 3 and/or layer 5. Also,in certain embodiments, CH₄ may be used as a feedstock gas during thedeposition process instead of or in combination with the aforesaid C₂H₂gas. Alternatively, any of the deposition methods disclosed in U.S. Pat.No. 5,858,477 may be used to deposit coating 3 and/or layer 5, thedisclosure of Pat. No. 5,858,477 hereby being incorporated herein byreference.

[0092] In certain alternative embodiments of this invention, secondsource 62 may deposit a ta-C:SiO:F coating 3 on substrate 1 instead of ata-C:SiO coating. The n, k and Tauc optical bandgap may be tailored bydoping the bulk of coating 3 with F and/or H; where “n” is refractiveindex and “k” is extinction coefficient. As the refractive index n ofglass is approximately 1.5, it is desirable in certain embodiments forthe refractive index n of coating 3 to be close to that of theunderlying glass substrate 1 in order to achieve good transmission andminimal reflection of the coated article. It is also desirable incertain embodiments for the “k” value to be low in order to achieve goodtransmission. In certain embodiments, the refractive index of coating 3is from about 1.4 to 2.0, more preferably no greater than about 1.75,and most preferably from about 1.5 to 1.7. The refractive index n of thecoating can also be altered using CF₄ or CF₆ as the doping gas.Fluorination of no more than about 5% atomic is preferred. The tablebelow shows variation of n & k with atomic F content: F % n @ 543 nm k @43 nm Eg(eV) 0 2.2 0.02 2.0 1.5 1.75 0.007 2.9 3.0 1.65 0.0001 3.7

[0093] Thus, fluorination provides a way in which to independently tunethe n & k to match desired optical properties of the substrate 1 inorder to improve transmission and the like. Fluorination may alsoscavenge a graphitic sp² fraction within the carbon matrix thus leavingmostly sp³ enriched carbon matrix.

[0094] Third ion beam source 63 is optional. In certain embodiments ofthis invention, the hydrophobicity of coating 3 can be further enhancedusing a plasma treatment by another source 63 or grafting procedureafter the main portion of DLC-inclusive coating 3 has been deposited.This technique using third source 63 removes certain polar functionalgroups at the outermost surface, thereby altering the surface chemicalreactivity (i.e. lowering surface energy) while the bulk of coating 3remains the same or substantially unaffected. After conveyor has movedthe DLC-coated substrate from the second source 62 station to a positionunder third source 63, the plasma treatment by source 63 introduceshydrogen (H) atoms into the outermost surface of coating 3, therebymaking the coating's surface substantially non-polar and less dense thanthe rest of the coating 3. These H atoms are introduced, because H₂ orArH₂ feedstock gas is used by source 63 instead of the C₂H₂ gas. Thus,third source 63 does not deposit any significant amounts of C atoms orSi atoms; but instead treats the outermost surface of the ta-C:SiOcoating by adding H atoms thereto in order to improve its hydrophobiccharacteristics. This plasma treatment may also function to roughen theotherwise smooth surface. It is noted that H₂ feedstock gas is preferredin ion beam source 63 when it is not desired to roughen the surface ofcoating 3, while ArH₂ feedstock gas is preferred in surface roughingembodiments. Additionally, a CF₄ RF induced plasma may be used toprovide a striation process with RMS roughness of at least about 100Å.

[0095] Contact angle θ of coating 3 with water increases with surfaceroughness as shown below, via certain examples performed in accordancewith certain embodiments of this invention: Sample No. Roughness RMS (Å)Contact Angle θ 1 5  101° 2 30 109° 3  120 117°

[0096] In certain alternative embodiments of this invention, thirdsource 63 may be used to introduce F atoms to the outermost 5Å layerportion of coating 3 (in addition to or instead of the H atoms) in orderto reduce surface energy. Flourination of no more than about 5% (atomicpercent) is preferred.

[0097] Coatings 3 according to different embodiments of this inventionmay have the following characteristics: coefficient of friction of fromabout 0.02 to 0.15; good abrasion resistance; an average density of fromabout 2.5 to 3.0 g/cm²; permeability barrier to gases and ions; surfaceroughness less than about 0.5 nm; inert reactivity to acids, alkalis,solvents, salts and water; corrosion resistance; variable or tunablesurface tension; tunable optical bandgap of from about 2.0 to 3.7 eV; IRtransmission @ 10 μm of at least about 85%; UV transmission @ 350 nm ofno greater than about 30%; tunable refractive index @ 550 nm [n=1.6 to2.3; k=0.0001 to 0.1], permittivity @ GHz 4.5; an undoped electricalresistivity of at least about 10¹⁰ Ω/cm; dielectric constant of about 11@ 10 kHz and 4 @ 100 MHZ; an electrical breakdown strength (V cm⁻¹) ofabout 10⁶; thermal coefficient of expansion of about 9×10⁻⁶/C; andthermal conductivity of about 0.1 Wcm K.

[0098] Referring to FIG. 13, in certain preferred embodiments of thisinvention, three separate ion beam sources 61-63 are used to make coatedarticles according to either of the FIG. 1-2 embodiments. However, inalternative embodiments, it is recognized that a single ion beam source(linear, curved, or the like) may be used to perform each of thecleaning step, the deposition step of DLC-inclusive coating 3, and theplasma surface treatment for introducing H and/or F atoms into theoutermost surface area of the coating. In such embodiments, thefeedstock gas may be changed between each such process.

ADDITIONAL EXAMPLE SAMPLE NOS. 1-3

[0099] Three additional example coated articles were manufactured andtested according to different embodiments of this invention as follows.They are additional Sample Nos. 1-3, each including a coating 3according to an embodiment of this invention deposited on glass usingtetramethyl-silane (TMS) and O₂ gas introduced within the linear ionbeam. All sample coatings 3 were of approximately the same thickness ofabout 750Å. A low energy electron flood gun was used to sharpen thespectral analysis conducted by x-ray photo electron spectroscopy (XPS)for chemical analysis. In XPS analysis of a coating 3, high energy x-rayphotons (monochromatic) impinge on the surface of coating 3. Electronsfrom the surface are ejected and their energy and number (count)measured. With these measurements, one can deduce the electron bindingenergy. From the binding energy, one can determine three things:elemental fingerprinting, relative quantity of elements, and thechemical state of the elements (i.e. how they are bonding). Componentsused in the XPS analysis (e.g. see FIGS. 14-15) include themonochromatic x-ray source, an electron energy analyzer, and electronflood gun to prevent samples from charging up; and an ion source used toclean and depth profile. Photoelectrons are collected from the entireXPS field simultaneously, and using a combination of lenses before andafter the energy analyzer are energy filtered and brought to a channelplate. The result is parallel imaging in real time images. Sample Nos.1-3 were made and analyzed using XPS, which indicated that the samplesincluded the following chemical elements by atomic percentage (H wasexcluded from the chart below). Sample No. C O Si F 1  54.6% 23.7% 20.5%  1.2% 2. 45.7% 21.7% 32.7% 0% 3. 59.5% 22.7% 17.8% 0%

[0100] H was excluded from the XPS analysis because of its difficulty tomeasure. Thus, H atoms present in the coating Sample Nos. 1-3 were nottaken into consideration for these results. For example, if Sample No. 1included 9% H by atomic percentage, then the atomic percentages of eachof the above-listed elements C, O, Si and F would be reduced by anamount so that all five atomic percentages totaled 100%.

[0101] FIGS. 14-15 illustrate actual XPS analysis of Sample No. 1. Thelarge hump in the FIG. 14 graph at approximately the 530-535 eV bindingenergy indicates that most of the Si—O and C—O bonds proximate thesurface of coating 3 are of the tetrahedral or sp³ type (i.e.tetrahedral bonds of these elements are at that particular bindingenergy). The large hump 70 in the FIG. 15 graph at approximately the282-288 eV binding energy indicates that the C—C and C—H bonds proximatethe surface of coating 3 are of the tetrahedral or sp³ type (i.e.tetrahedral bonds of these elements C and H are at that particularbinding energy). Smaller hump 71 in FIG. 15 is illustrative of C—F andO—C═O bonds in coating 3. Hump 72 in FIG. 15 is illustrative of C═Obonds in coating 3. Hump 73 is illustrative of C—O bonds in coating 3.It is noted that large hump 70 indicates that coating 3 may includebonds where a C atom is bonded to at least three other C atoms as wellas to a H atom via tetrahedral or sp³ type bonding.

[0102] Certain aspects of carbon (C) are now described generally, to aidin the understanding of this invention.

[0103] Carbon has the ability to form structures based on directedcovalent bonds in all three spatial dimensions. Two out of the sixelectrons of a carbon atom lie in the 1s core and hence do notparticipate in bonding, while the four remaining 2s and 2p electronstake part in chemical bonding to neighboring atoms. The carbon atom'sone 2s and three 2p electron orbitals can hybridise in three differentways. This enables carbon to exist as several allotropes. In nature,three allotropic crystalline phases exist, namely diamond, graphite andthe fullerenes and a plethora of non-crystalline forms.

[0104] For the diamond crystalline allotrope, in tetrahedral or sp³bonding all the four bonding electrons form σ bonds. The space latticein diamond is shown in FIG. 4 where each carbon atom is tetrahedrallybonded to four other carbon atoms by σ bonds of length 0.154 nm and bondangle of 109° 53″. The strength of such a bond coupled with the factthat diamond is a macromolecule (with entirely covalent bonds) givediamond unique physical properties: high atomic density, transparency,extreme hardness, exceptionally high thermal conductivity and extremelyhigh electrical resistivity (10¹⁶ Ω-cm).

[0105] The properties of graphite are governed by its trigonal bonding.The outer 2s, 2p_(x) and 2p_(y) orbitals hybridise in a manner to givethree co-planar sp² orbitals which form σ bonds and a p-type π orbital2p_(z) perpendicular to the sp² orbital plane, as shown in FIG. 5.Graphite consists of hexagonal layers separated from each other by adistance of 0.34 nm. Each carbon atom is bonded to three others by 0.142nm long σ bonds within an hexagonal plane. These planes are heldtogether by weak van der Waals bonding which explains why graphite issoft along the sp² plane.

[0106] As for amorphous carbon, there exists a class of carbon in themetastable state without any long range order. Material propertieschange when using different deposition techniques or even by varying thedeposition parameters within a single technique. In this category ofmaterials on one extreme we have ta-C (e.g. inclusive in coating 3 andlayer 5) which is the most diamond-like with up to 90% C—C sp³ bondingin certain preferred embodiments and on the other a-C (amorphouscarbon), produced by thermal evaporation of carbon, in which more than95% graphitic bonds are prevalent. In this respect, these two materialsreflect the intrinsic diversity of non-crystalline forms of carbon.

[0107] Coated articles according to any of the aforesaid embodiments maybe used, for example, in the context of automotive windshields,automotive back windows, automotive side windows, architectural glass,IG glass units, residential or commercial windows, and the like.

[0108] In certain embodiments of this invention, coating 3 has a contactangle of at least about 70°, more preferably at least about 80°, andeven more preferably at least about 100° after a taber abrasionresistance test has been performed pursuant to ANSI Z26.1. The testutilizes 1,000 rubbing cycles of coating 3, with a load a specified inZ26.1 on the wheel(s). Another purpose of this abrasion resistance testis to determine whether the coated article is resistive to abrasion(e.g. whether hazing is less than 4% afterwards). ANSI Z26.1 is herebyincorporated into this application by reference.

[0109] Once given the above disclosure, many other features,modifications, and improvements will become apparent to the skilledartisan. Such other features, modifications, and improvements are,therefore, considered to be a part of this invention, the scope of whichis to be determined by the following claims.

I claim:
 1. A coated glass article comprising: a glass substratecomprising, on a weight basis: SiO₂ from about 60-80%, Na₂O from about10-20%, CaO from about 0-16%, K₂O from about 0-10%, MgO from about0-10%, Al₂O₃ from about 0-5%; a hydrophobic coating includingdiamond-like carbon (DLC) and sp³ carbon-carbon bonds provided on saidglass substrate; and wherein said hydrophobic coating has an initialcontact angle θ with a sessile drop of water thereon of at least about100 degrees, and an average hardness of at least about 10 GPa.
 2. Thecoated glass article of claim 1, wherein said initial contact angle isat least about 110 degrees.
 3. The coated glass article of claim 2,wherein said initial contact angle is at least about 115 degrees.
 4. Thecoated glass article of claim 2, wherein said initial contact angle isat least about 125 degrees.
 5. The coated glass article of claim 1,wherein said coating has a surface energy Y_(C) of less than or equal toabout 20.2 mN/m.
 6. The coated glass article of claim 1, wherein saidcoating has a surface energy Y_(C) of less than or equal to about 19.5mN/m.
 7. The coated glass article of claim 1, wherein said coating has asurface energy Y_(C) of less than or equal to about 18.0 mN/m, andwherein the refractive index “n” of said coating is from about 1.5 to1.7.
 8. The coated glass article of claim 1, wherein said coating is indirect contact with said glass substrate.
 9. The coated glass article ofclaim 1, further comprising a DLC-inclusive layer disposed between saidcoating and said glass substrate.
 10. The coated glass article of claim1, further comprising a low-E layer disposed between said coating andsaid glass substrate.
 11. The coated glass article of claim 1, whereinsaid glass substrate is a soda lime silica glass substrate includingfrom about 66-75% SiO₂, from about 10-20% Na₂O, from about 5-15% CaO,from about 0-5% MgO, from about 0-5% Al₂O₃, and from about 0-5% K₂O. 12.The coated glass article of claim 1, wherein said hydrophobic coatinghas an average hardness of at least about 20 GPa.
 13. The coated glassarticle of claim 12, wherein said hydrophobic coating has an averagehardness of from about 20-80 GPa.
 14. The coated glass of claim 1,wherein said hydrophobic coating has a thickness of from about 100 -500Å.
 15. The coated glass article of claim 1, wherein the coated glassarticle comprises the following characteristics: visible transmittance(Ill. A): >60% UV transmittance: <38% IR transmittance:  <35%.


16. The coated glass article of claim 1, wherein said hydrophobiccoating includes sp³ carbon-carbon bonds subimplanted in a surface ofsaid glass substrate so as to strongly bond said coating to said glasssubstrate.
 17. The coated glass article of claim 1, wherein at leastabout 50% of carbon-carbon bonds in said hydrophobic coating are highlytetrahedral sp³ carbon-carbon bonds.
 18. A coated article comprising: asubstrate; a coating including diamond-like carbon (DLC) provided onsaid substrate, said coating including sp³ carbon-carbon bonds; andwherein said coating has an initial contact angle θ with a drop of waterof at least about 100 degrees, and an average hardness of at least about10 GPa.
 19. The coated article of claim 18, wherein said initial contactangle is at least about 110 degrees, and wherein said substrate issubstantially transparent to visible light.
 20. The coated article ofclaim 18, wherein said substrate is one of glass and plastic.
 21. Acoated glass article comprising: a glass substrate; and a hydrophobiccoating including diamond-like carbon (DLC) provided on said glasssubstrate, wherein said hydrophobic coating has an initial contact angleθ with a drop of water of at least about 110 degrees, and an averagehardness of at least about 10 GPa.
 22. The coated glass article of claim21, wherein said initial contact angle is at least about 115 degrees.23. The coated glass article of claim 22, wherein said initial contactangle is at least about 125 degrees.
 24. The coated glass article ofclaim 21, wherein said coating has a surface energy Y_(C) of less thanor equal to about 20.2 mN/m.
 25. The coated glass article of claim 24,wherein said coating has a surface energy Y_(C) of less than or equal toabout 18.0 mN/m.
 26. The coated glass article of claim 21, wherein saidhydrophobic coating is one of: (i) in direct contact with said glasssubstrate, and (ii) on said glass substrate in a manner such that atleast one low-E layer is disposed between said substrate and saidhydrophobic coating.
 27. The coated glass article of claim 21, whereinsaid hydrophobic coating has an average hardness of from about 20-80GPa.
 28. The coated glass article of claim 27, wherein the coated glassarticle comprises the following characteristics: visible transmittance(Ill. A): >60% UV transmittance: <38% IR transmittance:  <35%.


29. The coated glass article of claim 21, wherein at least about 50% ofcarbon-carbon bonds in said hydrophobic coating are highly tetrahedralsp³ carbon-carbon bonds.
 30. The coated glass article of claim 21,wherein the outermost 10Å layer portion of coating 3 includes in atomicpercentage: from about 5-60% carbon (C), from about 0-40% oxygen (O) ,from about 0-40% silicon (Si) , from about 10-95% hydrogen (H), and fromabout 0-10% fluorine (F).
 31. The coated glass article of claim 21,wherein at least one 10Å thick layer portion of the coating includes inatomic percentage: from about 15-80% carbon (C), from about 5-45% oxygen(O), from about 5-45% silicon (Si), from about 0-30% hydrogen (H), andfrom about 0-10% fluorine (F).
 32. The coated glass article of claim 21,wherein a ratio of carbon (C) to silicon (Si) in said coating is fromabout 1:1 to 4:1.
 33. The coated glass article of claim 21, wherein theoutermost 5Å layer portion of said coating includes in atomic percentageat least about 25% H.
 34. A coated glass article comprising: a glasssubstrate; and a coating including diamond-like carbon (DLC) provided onsaid glass substrate, wherein the outermost 5Å of said coating includesin atomic percentage at least about 50% H.
 35. The coated glass articleof claim 34, wherein said coating has an initial contact angle θ of atleast about 110 degrees, and an average hardness of at least about 10GPa.
 36. The coated glass article of claim 34, wherein said coating hasa surface energy Y_(C) of less than or equal to about 18.0 mN/m.
 37. Amethod of making a coated article, the method comprising the steps of:providing a substrate; and depositing a highly tetrahedral amorphouscarbon (ta-C) inclusive coating having more sp³ carbon-carbon bonds thansp² carbon-carbon bonds on the substrate in a manner such that the ta-Cinclusive coating has an initial contact angle θ of at least about 100degrees.
 38. The method of claim 36, further comprising depositing theta-C inclusive coating in a manner such that the ta-C inclusive coatinghas an initial contact angle θ of at least about 115 degrees.
 39. Themethod of claim 37, further comprising plasma treating an outmostsurface of the coating in order to provide at least H atoms in thecoating proximate the outermost surface thereof, so as to reduce surfaceenergy of the coating.
 40. The method of claim 37, wherein saiddepositing step is carried out using at least plasma ion beamdeposition.
 41. The method of claim 40, wherein said depositing stepincludes using at least one of H₂ and acetylene feedstock gas.
 42. Themethod of claim 40, wherein said depositing step includes varying ionenergy within a range of from about 100 to 800 eV during said depositingso that the coating has different layer portions having differentdensities.
 43. An automotive window comprising: a substrate transparentto at least about 70% of visible light rays; a highly tetrahedralamorphous carbon inclusive coating provided on said substrate, whereinsaid coating has a thickness of from about 50 to 1,000 Å and asubstantial number of sp³ carbon-carbon bonds; wherein the automotivewindow comprises the following optical characteristics: visibletransmittance: >70% UV transmittance: <38% IR transmittance:  <35%;

wherein said coating has an initial contact angle of at least about 100degrees.
 44. The automotive window of claim 43, wherein said substrateincludes one of soda lime silica glass, borosilicate glass, andsubstantially transparent plastic, and wherein said coating has anaverage density of at least about 2.4 gm/cm³.
 45. A coated glass articlecomprising: a glass substrate; at least one hydrophobic coatingincluding diamond-like carbon (DLC) provided on said substrate; andwherein at least one 10Å thick layer portion of said hydrophobic coatingincludes, in atomic percentage, from about 15-80% carbon (C), from about5-45% oxygen (O), from about 5-45% silicon (Si), from about 0-30%hydrogen (H), and from about 0-10% fluorine (F).
 46. The coated glassarticle of claim 45, wherein a ratio of carbon (C) to silicon (Si) in atleast one portion of said coating is approximately 1:1.
 47. A coatedarticle comprising: a glass substrate; a coating including diamond-likecarbon (DLC) provided on said glass substrate, said coating includingsp³ carbon-carbon bonds; and wherein said coating is doped so as to havean index of refraction “n” of no greater than about 1.75.
 48. The coatedarticle of claim 47, wherein said coating includes C, Si, and F atoms,and wherein an atomic ratio of C to Si in said coating may be from about1:1 to 4:1.
 49. A method of cleaning a glass substrate comprising thesteps of: providing a linear ion beam source; directing an ion beam fromthe source toward the glass substrate in a manner so that impurities ona surface of the glass substrate are removed by the ion beam; and saiddirecting step being performed in a manner so as to create free radicalson the surface of the substrate.